Catalyst for hydrocarbon conversions



March 8, 1966 R. H. LINDQUIST ETAL 3,239,456

CATALYST FOR HYDROCARBON CONVERSIONS Filed July 5, 1964 META| SURFACEvs. METAL CONTENT x\ Ni F2 TREATMENT [Ni (N03); IMPREGNATION l l l l l ll o 5 1o 15 2o 25 3o 35 4o WEIGHT Ni ON CATALYST INVENTORS ROBERT H.L/NDQU/ST ROGER O B/LLMAN TTORNEYS United States Patent pany, acorporation of Delaware Filed July 3, 1964, Ser. No. 380,148 4 Claims.(Cl. 208111) This is a continuation-in-part of application Serial No.30,373 filed May 19, 1960, now Patent No. 3,140,925.

This invention relates to the manufacture of new catalysts containingalumina or magnesia as essential components of the support, and alsocontaining in special form certain metals and fluoride, which catalystshave particular value in the conversion of hydrocarbon oils. Also, theinvention pertains to novel catalysts of improved activity.

The invention contemplates the manufacture of an improved catalystcontaining at least alumina or magnesia, as well as highly dispersedmetal, particularly hydrogenating metal components, and fluoride. Theresultant highly active catalysts are quite useful in hydrocarbonconversions. More specifically, when the catalyst base or support hasappreciable cracking activity such as an activated silica-alumina, themetal-fluoride-treated catalysts of the present invention haveoutstanding properties as low temperature hydrocracking catalysts. Suchcatalysts, particularly after sulfiding, can be employed in lowtemperature hydrocracking processes for long periods of operation togive high conversions to desirable products with a minimum of normallygaseous material such as methane and with a low catalyst fouling rate.Catalysts giving even less fouling are those in which residualwater-extractable fluorides have been removed before use.

We have found that by contacting an activated (i.e. substantiallydehydrated) alumina or magnesia support or base material for asufliciently long period with an aqueous solution of fluoride ofcatalytically active metal, a superior catalyst is obtained in that themetal of the fluoride becomes associated with the base in a much greaterdegree of dispersion than heretofore obtainable by conventional means,such as impregnation of the same base with other salts of the samemetal. A particular feature of the present method is that it yieldscatalysts with very high metal surface areas for each unit of weight ofadded metal. Also, the added metal tends to increase the total surfacearea of the catalyst rather than decrease the overall surface area asgenerally happens with other methods such as the usual metalimpregnations. Furthermore, the amount of metal that can be incorporatedinto the base is much greater for the method of the present inventionthan obtainable heretofore by a single impregnation from an aqueoussolution of other salts of the metal. In prior impregnation methods, theamount of metal deposited in a single impregnation is generally limitedto the amount of metal contained in an amount of a saturated metal saltsolution equal in volume to the pore volume of the particular alumina ormagnesia-containing base (which amount is hereinafter referred to as apore volume of the impregnating solution).

The extraordinarily high degree of dispersion for the added metal asobtained by the present invention is shown by the following comparison,wherein CO chemisorption values, as described hereinbelow, are used tomeasure the surface area of the added metal. Calcined alumina-silicaparticles (containing about dehydrated alumina and having a surface areaof about 375 square meters per gram, as measured by nitrogen adsorption)were impregnated with a saturated nickel nitrate solution and, aftersubsequent drying at 250 F. for 5 hours, were calcined at 900 F. for 2hours. These impregnated particles were then treated with aqueoushydrofluoric acid at room Patented Mar. 8, 1966 temperature andthereafter calcined at 800 F. for 3 hours in a hydrogen atmosphere. As aresult, an active catalyst was obtained containing 11 wt. percent nickeland 5.6% fluoride. This catalyst adsorbed 220 micromoles of CO per gramof nickel. Another catalyst prepared from similar alumina-silicaparticles (containing about 25% alumina) by treatment with aqueousnickel fluoride solution in accordance with the present invention, gaveabout the same percentages by weight of nickel fluoride, namely, 10.3%nickel and 5.4% fluoride. This second catalyst chemisorbed 500micromoles of CO per gram of nickel, indicating a degree of dispersionfor the nickel of more than twice as great as that for the catalystprepared by impregnation with nickel nitrate. Such substantial increasesin metal surface are highly desirable because of their directcorrelation with catalyst activity.

One unusual feautre of the present invention is that the treatment withmetal fluoride, particularly with nickel fluoride on alumina-silica,results in a relatively increased total surface area such that thetreated catalyst appears to be dentritic. Thus a catalyst prepared bytreatment of a calcined alumina-silica support with nickel fluoride to a24 wt. percent Ni content had a total surface area of 415 mF/gm. (asmeasured by nitrogen absorption according to the Brunauer et al. methodreferred to hereinbelow). This result shows increased surface areacaused by the nickel fluoride treatment, assuming even that thealumina-silica support lost none of its original surface area and hencecontributed 320 m. gm. to the total surface area of the finishedcatalyst. In contrast, a catalyst prepared from the same calcinedalumina-silica support by impregnations with nickel nitrate to about thesame nickel content had a total surface area of 180 m. /gm., indicatingthat original surface area of the support was lost.

The brief description of method and the resulting catalyst indicates thegeneral nature of the invention, but before describing these aspects ofthe invention in detail together with particularly preferred aspects, itwill be observed that both the catalyst preparation method and catalystsresulting therefrom are novel and have obvious advantages over the priorart. As desired, the highly dispersed metal on the alumina ormagnesia-containing base can be converted to various forms such as thereduced metal, the oxides, sulfides, etc., to yield novel catalystshighly active for different hydrocarbon conversion and other processes.

It is found that in the present method the metal fluoride is adsorbedupon the alumina or magnesia base to yield an adsorbed metal fluoride ina high degree of dispersion, that is, with a large metal surface area.The method also yields in a single contacting step a relatively largeamount of metal per unit area of base treated. While the explanation forthis phenomenon is not intended to be limiting on the invention, it isbelieved that the mechanism involves a chemisorption phenomenon. Themetal and fluoride contents of the aqueous treating solution decrease inabout the molecular proportions and no more than relatively minorchanges in pH have been observed for the several metal fluorides tested.These various factors apparently affect the nature of the resultingcatalyst.

Further, although the present method utilizes activatedalumina-containing or magnesia-containing catalyst sup-port, the metalfluoride treated catalysts resulting from the present method differ fromthe products obtained by treating alumina and/ or silica catalysts withhydrofluoric acid, or similar sources of fluorine, subsequent to orprior to metal impregnation, in that the present method depends upon theuse of essentially neutral metal fluoride solutions and results in addedmetal of high surface area and simultaneous addition of fluoride.Suflice it to most instances through .the subsequent sulfiding or other.

normal catalyst treating operations. Moreover, the fluoride contentremains unusually constant through subsequent reduction, sulfiding andhydrocracking test runs.

The increased surface area of the added metal which characterizes thepresent catalyst, while set forth in detail in succeeding portions ofthe specification, can be seen further by reference to the datapresented in the accompanying drawing, where-in the figure is a graphshowing the contrast in surface per gram of nickel from the COchemisorption values for a nickel fluoride ,on silica-alurnina catalystprepared in accordance with the present invention and for afluorided-nickel catalyst prepared by impregnation of essentially thesame alumina-silica support with nickel nitrate and subsequentconversion to nickel and treatment with hydrogen fluoride. When usingnickel nitrate, the higher metal contents had to be obtained by resortto a plurality of impregnations. the lower curve in the graph .wasprepared from aluminasil-ica containing about 10% dehydrated alumina andhaving a'surface area of about 375 m. /gm. as measured by nitrogenadsorption, which support had been calcined at 800 F. for 2 hours. asaturated nickel nitrate solution, then dried for 5 hours at 250 F.,calcined at 900 F.,for 2 hours, and reimpregnated with nickel nitrate,as needed." Then, the impreg 1 nated catalyst was treated with aqueoushydrofluoric acid at room temperature and thereafter calcinedat800 F.for 3 hours in a hydrogen atmosphere. The catalyst of the presentinvention as shown in the upper curve, was prepared from alumina-silicacontaining about dehydrated alumina and having a surface area of'about550 m. /gm., by contacting the alumina-silica with an aqueous solutionof nickel fluoride for sufficiently long pe-,

riods to chemisorb thereon the desired amount of nickel. and thereafterdried at 300 F. for 4 hours and then calcining the product at 900 F. for3 hours in hydrogen.

The data in the figure illustrates that the surface area of the addedmetal for the present catalyst is much greater at all added metalcontents, than catalysts prepared by methods of impregnating With ametal salt followed by subsequent decomposition of the impregnatedsalt.The data also illustrate that the present catalyst has difierentproperties from one prepared by impregnation with a non-fluoride salt ofa catalytic metal, and a subsequent fluoriding treatment such as withhydrofluoric acid. Also to be noted is that with the present method onlyone contact with metal-containing solution was needed to obain thedesired amounts of added metal.

The alumina or magnesia in the base material must be in the activatedform prior to'treatment in accordance with the present invention.

and alumina-silica hydrogels, are not only first dried but also aresubjected to high temperatures in the range of at least 800 F. up toabout 1500 F. for a sutlicient time to remove both physically held waterand most of the chemically bound water, and to leave the. surfacesubstantially The catalysts of Thus, the various aluminas. andalumina-containing base materials, such as alumina This catalyst wasimpregnated with 4% or activation treatment also tends to. removevolatile substances such as ammonia which might interfere with thecombination with the metal fluoride in the subsequent contacting step.Preferably, such alu'minas and silicaaluminas will have a high. surfacearea of-atleast 300E rn. gm. When less active, though usually lesspreferred,

supports are desired, such as with dehydrogenation catalysts, thesupport can have asurfacearea of downto. 100 ru /gm. Themagnesiaacontaining supports are acti- .vated in a simila-r fashionnOther than activated alumina per se, various sup-- orts containinactivated alumina can be used such as P mixtures of alumina with othermaterials including silica; however, alumina is greatly-preferred whenthe hydrofining activity of the .catalystvis tobe emphasized, and

siliceous aluminas when hydrocrackingis desired. Like-- wise, varioussupports containing or composed of, acti-.

vated magnesia can be em ployed, such as magnesia-silica:magnesia-silica-zirconia and the like. For most purposes,

the alumina-containing supports are preferred because of their generallygreater'healt stability and hence, the-invention is illustratedhereinafter mainly; with the alumina: containing supports. V

The siliceous alumina bases preferred for the low temperaturehyd-rocracking conversion process can be any synthetic or naturalsiliceous alumina composition of acid character which is effective forthe, cracking of hydrocar The siliceous alumina base, before addition ofthe bons. hydrogenation component thereon, should contain at leastabout1%,' and preferably at least 10% by wt. of alumina calculated as A10 From the cracking activity stand- .point, the siliceous alumina baseof the catalyst in its'presilica-alumina-ma-grresia catalysts. Apreferred factive siliceous alumina cracking base for usein the catalystof this invention is comprisedof a synthetically prepared.

composite of silica and. alumina containing from about 10 to 40% byweight of the alumina component.

The. preferred class of siliceous alumina cracking bases can be preparedby any one of several alternatemethods; For example, anaqueous solutionof an aluminum salt, suitably adjusted in acidity, may be combinedwith asolution, of. sodium 'silicate .under such conditions that thecorresponding gels are coprecipitatedvinintimate admixture. On the otherhand, silica ,gel andalumina gel may be separately prepare-d andthenmixed inthe .de-

sired proportions. Alternately, a formed silica gel can be.v 7

treated with an aqueous solutionof an aluminum salt,

' and the alumina precipitated in the silica gel by the addidehydrated,i.e., only slightly hydrated with chemically purpose, with shorter timesbeing used for the highertemperatures. Such high temperature treatmentresults in a substantially dehydrated alumina base wherein the alu-,

mina is in the activated alumina form. The calcination suchasare knownas gamma, eta, theta and chi aluminas, by exposure to calciningtemperatures, as described hereinabove. When such activated supports aretreated by the present method, the resulting catalysts have goodmechanical strength. andv the, added metal, rather than having anappreciable amount lost into the substrata of;

Thus, rather than the so-called dried the support, has a large surfaceexposed for promotion of hydrocarbon conversions.

Similarly, activated magnesia-containing supports can be prepared foruse in this invention. Thus, a silica gel may be impregnated with amagnesium salt which is then precipitated in the gel by treatment of thegel With ammonia. Alternatively, a silica hydrogel can be thoroughlymulled with magnesia or magnesium hydroxide, or a slury of magnesia canbe aded to a silica hydrosol which is allowed to gel. Such products areusually washed and dried, but for use in the present invention thefurther treatment of substantial dehydration as described above isessential. Similarly, silica-alumina-magnesia and other alumina and/ ormagnesia-containing supports can be prepared.

The improved method of preparing metal fluoride alumina base catalystsincludes as an essential step the contacting of an activated aluminabase for an appreciable time period with an aqueous solution of afluoride of certain metals, especially the transition group metals,particularly at their lower valence. Usually it is preferred to employmuch more metal fluoride than will be contained in one pore volume(calculated for the particular alumina base being used and the amountthereof) of a saturated solution of that metal fluoride. Such preferredoperation involves either using increased volumes of the metal fluoridesolutions, or having in contact with the aqueous solution a sufficientamount of solid metal fluoride to keep the solution saturated.

As indicated, the metal fluorides are preferably the fluorides of themetals having hydrogenation-dehydrogenation activity. Usually the irontransition group metals, and especially nickel, are most preferred sincethey tend to promote electron transfer reactions to a greater extentthan other metals. Other desirable properties of this group of metalsinclude their ready conversion to sulfides and like compounds which arenot readily reduced in hydrogen atmospheres under normal operatingconditions. More broadly desirable are the groups of metals havingatomic numbers from 23 through 30. Particular fluorides are nickelousfluoride, cobaltous fluoride, vanadium fluoride, cupric fluoride, andtheir hydrates. Also useful are the fluorides of metals such aschromium, zirconium, palladium, aluminum and others so long as they aresufiiciently stable in water solution. Normally, the fluorides of metalsother than those of the oxides in the metal oxide support are preferred,particularly when dual function catalysts are desired. The aqueoussolutions of the metal fluorides can be diluted or concentrated but aregenerally the latter for minimizing the volumes employed. Often,particularly with the metal fluorides of low solubility, it ispreferable to employ an excess of solid metal fluoride over the amountwhich will saturate the Water used. It is usually desirable to useenough Water so as not only to cover the volume of alumina-containingcatalyst support employed but also to provide for agitation to aidcontacting and dissolution of the metal fluorides. If desired, theexcess solid metal fluoride can be kept separated from the catalystsupport by means of a porous plate or filter. Enough metal fluorideshould be present to give a metal content in the alumina-containingsupport of at least 1% by weight, and preferably in the range of 3 to40%, based upon the support employed. Ordinarily, the amount of metalfluoride will be the amount desired to be added to the alumina supportto attain the activity desired for the selected catalytic conversion.Usually the amount of metal fluoride desired will be appreciably morethan, e.g., at least twice, the amount of metal fluoride that Will becontained in one pore volume of a saturated solution of that metalfluoride. The aqueous metal fluoride solution can contain a plurality offluorides such as of metals which cooperate in certain catalyticreactions. Fluorides of the two or more metals will become associatedwith the alumina-containing support during the contacting step. Forexample, a combination desirable for hydrofining, e.g., sulfur removal,is that of nickel and cobalt, and these metals can be simultaneouslyincorporated into an alumina-containing support by one treatment with asolution of the two fluorides. The ability to add more metal in onecontacting treatment is often an important advantage of the presentmethod over prior methods where a plurality of metals are to be added insuccessive treatments with aqueous solutions and the first added metaldissolves readily in aqueous solutions.

The activated alumina catalyst support is kept in contact with the metalfluoride solution until the desired amount of metal fluoride becomesassociated with or bound to the support. For example, suflicient time isallowed to add preferred amounts such as at least equivalent to 2 porevolumes of saturated metal fluoride solution. Normally this contactingstep is conducted at room temperature, and where the alumina-containingsupport is finely divided such as in powdered form, or spray dried meshparticles, contacting for at least 3-4 hours, preferably overnight(i.e., about 16 hours), at room temperature will be satisfactory. Longertimes are allowed for obtaining the higher metal contents in thesupport; for example, with adequate agitation at room temperature about3 days contact between a calcined silica-alumina in powdered or spraydried form and a NiF solution maintained saturated, a catalystcontaining about 40% Ni and about 23% F is obtained. When the activatedalumina support has a larger particle size, longer contact times arealso used. By raising the temperature such as to l50200 F., the contacttime may be lessened. Desirably, the temperature is adjusted so that therequired amount of metal fluoride is added in about 1 to 2 hours contacttime. However, since the chemisorption of the metal fluorides by thesupport is a relatively slow reaction, the contacting time is preferablyat least three hours (temperature in the range from about roomtemperature to near the boiling point of water, i.e., about 200 F.) whenthe desired resulting metal content is about 3 wt. percent and moreparticularly when above 5 wt. percent. The alumina-containing support ispreferably finely divided to a particle size below about 50 mesh, inorder to obtain more nearly uniform dispersion of the metal throughoutthe support, particularly with added metal contents above 10% by Wight.

The treating solution is essentially only metal fluoride, or a pluralityof metal fluorides, and Water; materials such as ammonia or amines orother .basic materials or substances reactive with the support or metalfluorides are to be avoided.

After contacting the alumina-containing base with the metal fluoridesolution for a suflicient time, the excess solution is decanted from thetreated alumina base and the resultant metal fluoride alumina catalystis then dried, preferably at relatively low temperatures (i.e., 250 to500 F.) to avoid surface loss. Thereafter the metal fluoride aluminacomposition can be used as such but is normally subjected, as indicatedhereinabove, to subsequent treatments prior to use. Thus the metalcontent may be converted, at least partially, to other catalyticallyactive metal compounds such as to the sulfides or to other compounds,stable at the conditions of use, with members of Groups V and VI of theperiodic table. When the catalyst is to be employed in at leastpartially sulfided form, as for low temperature hydrocracking, the driedcatalyst is treated under sulfiding conditions preferably below 750 F.,with a gaseous sulfiding agent, either directly or after intermediatetreatments. Preferably, in order to keep the sulfiding temperature lowand to obtain a more active sulfided metal fluoride catalyst, the driedcatalyst such as the nickel fluoride silica-alumina catalyst, is firstsubjected to a reducing atmosphere at temperatures of the order of 800to 1100 F., usually for three to ten hours, and preferably above about850 F. for at least four hours. More specifically, the metal fluoridealumina-containing base resulting from the contacting of the aluminabase with metal fluoride solution is dried, for example, for ten hoursat temperatures of 250 P. Then the dried/catalyst is heated for five tosix hours at about 900 F. in a stream of hydrogen. Normally insuchtreatments the metal fluoride alumina-containing catalyst suffers nosubstantial loss of fluoride. Alternatively, the dried catalyst can becalcined in air and thereafter, if desired, the metal oxide (i.e., theoxide of the added metal) reduced to the metal.

sulfide hydrocrackin-g catalysts containing water-extract? ablefluoride, such as nickel catalysts treated wiwth HF,

B1 or the like, have high deactivationrates, probably due to thecracking activity of such fluoride, the presentv catalysts withsubstantially no water-extractable fluoride content will give lowfouling rates and can be used in the hydrocracking process for longperiods without deactivation. While catalyst prepared as set forth abovehas a low level of water-extractable fluoride relative to the totalfluoride concentration, an even further improvementin the hydrocrackingprocess is obtained by removing the trace of water-extractable fluoridedue to metal fluoride not chemisorbed but remaining on the surface ofthe support. For this purpose the catalyst, after the contactingtreatment, is washed with water. Preferably, the alumina or magnesiacontaining support with catalytic metal fluoride chemisorbed thereonisfirst dried and then either calcined in air or reduced to the metalbefore water wash-v ing, the latter being especially preferred. Thewaterextraction can be carried out in any suitable manner, usually withhot water. In the laboratory, washing in a Soxhlet apparatus was foundsatisfactory. The washing is continued until the wash water shows byanalysis substantial absence of fluoride. tains fluoride but notwater-extractable fluoride such'as results from prior impregnationtechniques.

Thereafter, the catalyst is subsequently sulfided with a gaseoussulfiding agent under sulfiding conditions. It can be contacted withhydrogen sulfide or with hydrogen and organic sulfide at temperaturesbelow about 750 F., and preferably below 700 F. For example, thesulfiding treatment can be effected at 1200 p.s.i.g. and 550-6 F., withhydrogen present in the amount of about 8000 s.c.f. per barrel of feedwhich can be made up of mixed hexanes containing, for example, 10% byvolume of dimethyl disulfide. Alternatively, other sulfur compounds,such as hydrogen sulfide or carbon disulfide, mercaptanszor otherorganic sulfides or disu'lfides can be used.

Optionally, after the metal fluoride treatment other metals can be addedsuch as by the normal impregnation techniques. For example, aftertreatment with a mixture of nickel fluoride and cobalt fluoride, thecatalyst can be dried and then impregnated with ammonium molyb-- dateand calcined to yield a Ni-Co-Mo catalyst suitable for hydrofining.

In the preparation of the catalyst, preferably afterthe steps of metalfluoride contacting and subsequent drying but preferably beforereduction and/or sulfiding, the catalyst is transformed to the desiredshape. The catalyst can be used in the form of pellets, beads, extrudedor other particle shapes. When the support has been treated in thepreferred finely divided form, the resulting treated support isdesirably converted into pellets or other largersized particles with theaid of a die lubricant, such as.

a hydrogenated vegetable oil, polyvinyl alcohols, or the like which isburned out usually before reducing treatment, if any, and sulfiding.Good results have been obtained with a catalyst mass made up of smallbeads having an average diameter of about inch, as well as with acrushed aggregate prepared from Said beads. Some of the catalysts in thepowdered or spray dried forms are useful for so-called fluidizedoperation.

To illustrate the present invention, the following ex- The resultingcatalyst con 8f; amples of preparations of catalysts are given,whereinsurface areas of the alumina-containing supports are measured bynitrogen absorption according to the method of Brunauer, Emmett andTeller as described in J. Am.

Chem. Soc., 60, 309 (1938). In the COchemisorption method of determiningthe surface. area of the added.

metal, aknownmixture of carbonmonoxide, carbon-14 monoxide, and heliumor other inert gas is pumped at a constant rate over the calcined andreduced metal-containing catalyst'and the concentration of' the CO inthe efliuent gas is calculated from' the. declining .count ofradioactive disintegrations of carbon- 14 monoxide. A

detaileddescription of the CO chemisorption method is given by T..- R;Hughes, R. P., Sieg and R. J. Houston in A.C.S. Petroleum DivisionPreprints, vol. 4, No. 2,

page C33 (1959).

Example ,1

A calcined silica-alumina catalyst containing 25%" alumina (AerocatTriple A) inspray-dried' powder form, and having a pore volume of 0.89cc./gm.' and a surface area of 500 meters /gram as measured by nitrogenisotherm was employed. About 10-15 cc. of such silicaalumina at atemperature of about 250 F; was introduced into about 200 cc...of afiltered,- saturated solution of nickelous fluoride .(2.6 gms./ ml.) andallowed to stand overnight. The excess solutionwas separated from thecatalyst by filtering; The solution had partially decolorized and thetreated catalyst had a green color. The solid catalyst was driedat 300F. for 3 hours. An analysis showed 6.05 wt. percent Niand 2.3% F.

. Example 2 and .33 wt. percent F., from.whichit was calculated that-thecatalyst contained 21 wt. percent Ni'and 12% F;

on a dry basis. The treated. catalyst after drying for r 3 hours at- 300analyzedas containing 23% Ni and 8.9% F;

Example 3 Into a vessel containing a saturated solution of NiF wasintroduced a calcined silica-alumina catalyst containing 25% alumina.(Aerocat Triple A having a surface v area of 500 mF/gm. and a porevolume of 0.89 cc./gm.).

A porous container. of nickelous. fluoride tetra-hydrate crystalsWasimmersed in the NiFg solution." The supernatant solution over thecatalyst was stirred for 83 hours at room temperature and thenthe.treated catalyst was separated from the solution. After drying at 600for 4 hours, the catalyst contained 12.2 ;wt..percent'Ni and 6.4% F.

Example 4, a

Two preparations-were made up at the, same time to" compare the effectof temperature on the time for chemisorbing the metal fluoride in thelarger amounts normally desired. Each of thesev preparations used 100gms. of

an activated alumina in spray-dried formand 67.89 gms.

of cobaltous fluoride dehydrate together with enough Water to make .1liter. Preparation A was kept at a temperature in the range of about 200F. and preparation B was kept'at room temperature.v Both preparationswere continuously stirred and water-was added from time to time tomaintain the. volume. at .1 liter. As determined by following theoptical density of the solutions, the cobalt'fluoride'was chemisorbedionthe alumina support in both preparations at about the same rate for thefirst two to three hours. of the cobaltfluoride by the support'continuedat about the same rate in the heated preparation but at an appre-.

Thereafter the chemisorption ,9 cia-bly slower rate in preparation B atroom temperature. This indicates that for the higher desired amounts ofmetal fluoride increased temperatures are helpful in minimizing theadditional time required to chemisorb substantially all the metalfluoride in the contacting solution.

Example About three volumes of 20-26 mesh alumina (Filtrol 90) which hadbeen calcined at 600 F. for 4 hours and had a surface area of 240 m. gm.and a pore volume of 0.40 cc./gm. was placed in a vessel along withvolumes of 1.4% aqueous nickel fluoride solution. The mixture wasstirred overnight at room temperature, then filtered, dried at 400 F.for 9 hours and calcined at 900 F. for 4 hours. The product contained5.73% Ni and 2.04% F. Such catalyst can be used for isomerization.

Example 6 The product of Example 5 was further treated as follows: Aboutone volume of an aqueous solution containing equal parts ammoniummolybdate, concentrated ammonium hydroxide and water, was poured overabout 2 volumes of the above product. After standing 10 minutes, themixture was filtered, dried at 400 F. for 9 hours and calcined at 900 F.for 4 hours, whereby the molybdate was converted to the oxide. The finalproduct contained 10.6% M0, 4.8% Ni and 1.7% F.

Example '7 About 6 volumes of activated, 200 mesh silica-alumina(Aerocat Triple A) containing 25% alumina and having a surface area of500 m. /gm. and a pore'volume of 0.89 cc./gm., was placed into 100volumes of 0.2 Wt. percent aqueous solution of cobaltous fluoride. Afterstanding 24 hours the supernatant solution was colorless, indicatingsubstantially all the cobaltous fluoride had reacted with the calcinedsilica-alumina. After standing several days, the catalyst was filteredand dried for 3 hours at 300 C. The catalyst then contained 3.74% Co and3.05% F.

Example 8 About 6 volumes of activated, 200 mesh silica-alumina (AerocatTriple A) containing 25 alumina, and having a surface area of 500rnF/gm. and a pore volume of 0.89 cc./grn. was placed into 100 volumesof 0.2 Wt. percent aqueous solution of cobaltic fluoride. After standing24 hours the supernatant solution was colorless, indicatingsubstantially all the cobaltic fluoride had reacted with the calcinedsilica-alumina. After standing several days, the catalyst was filteredand dried for 3 hours at 300 C. The catalyst then contained 2.02% Co and2.34% F.

Example 9 About 6 volumes of activated, 200 mesh silica-alumina(Aeroc-at Triple A) containing 25 alumina and having a surface area of500 m. /gm. and a pore volume of 0.89 cc./gm. was placed into 100volumes of 0.2 wt. percent aqueous solution of chromium fluoride (CrF .2/2H O) After standing 24 hours the supernatant solution was colorless,indicating substantially all the chromium fiuoride had reacted with thecalcined silica-alumina. After standing several days, the catalyst wasfiltered and dried for 3 hours at 300 C. The catalyst then contained1.26% CI and 1.12% F.

Example 10 A calcined silica-alumina catalyst in spray-dried powderedform (60 micron average particle size, con taining 25% alumina andhaving a pore volume of 0.8 cc./gm.) was contacted with stirring for 78hours with a saturated aqueous solution of nickelous fluoride at a ratioof 2 volumes of catalyst to volumes of the so- 10 lution. The treatedcatalyst was filtered and then washed three times with distilled water.After drying for 16 hours at 300 F., the catalyst analyzed as containing23.9 wt. percent Ni and 13.7% F.

Example 11 About 1 volume of alumina-silica in spray-dried powdered form(200 mesh) (and containing about 13% alumina and having a surface areaof 500 mP/gm. and a pore volume of .74 cc./gm.) was placed in a vesselwith 30 volumes of water containing a porous thimble filled with NiF .HO and allowed to stand at room tem perature for 11 days with somestirring of the slurry of the alumina-silica and nickel fluoridesolution. After drying in a kiln for 3 hours at 300 F., the catalystanalyzed as containing 41% Ni and 18% F.

Example 12 Activated alumina powder with a surface area of about 300mP/gm. as measured by nitrogen isotherms, has a CO chemisorption valueof about 4 micromoles/ gm. After contacting such beads with an aluminumfluoride solution for 24 hours at F., the catalyst had, after drying andcalcining, an increased aluminum content of 3 wt. percent Al (calculatedas metal from the amount removed from the solution in the contactingperiod), a substantially increased CO chemisorption value of the orderofl2 micromoles/gm., and a fluoride content of about .4%. The resultingcatalyst had a surface with an excess of aluminum atoms and is superiorto a catalyst prepared by mixing aluminum salts including fluoride withalumina hydrogel, in that the former has substantially increasedactivity for isomerization.

Example 13 Activated magnesia with a surface area of 300 m. /gm., in 200mesh powdered form, was contacted in a 1:15 volume ratio with asaturated aqueous nickel fluoride solution with stirring for 24 hours atroom temperature. The catalyst, after drying at 300 F. for 3 hours,contained 6.8 wt. percent Ni and 3.3% F.

Example 14 A calcined silica-alumina containing 25% alumina inspray-dried powdered form and having a pore volume of 0.89 cc./gm. and asurface area of about 500 square meters per gram as measured by nitrogenisotherm was employed. 123 gms. of such silica-alumina, together with 4liters of distilled water and 99.92 gms. of cobaltous fluoride wasstirred for 11 hours at room temperature. The solid material wascollected by filtering through a Buechner funnel and then dried for 3hours at about 150 C. The dried product contained 25.4% C0 and 9.8% F.

Example 15 A calcined alumina in spray-dried powdered form and having apore volume of 0.5 cc./gm. and a surface area of 200 rn. gm. was used inan amount of gms. and along with 152 gms. of CoF .2H O and 2.48 gms. of3.36 gms. of CuF .2H O and NiF .4H O, respectively, were added to oneliter of distilled water and stirred continuously for 24 hours, allowedto stand without stirring for 18 hours and then stired continuously for42 hours at room temperature. The treated aluminas were vacuum filteredand then dried for 5 hours at about 200 C.

The above preparations had the following analyses:

(1) 34.9% cobalt and 0.1% copper (calculated as metal) (2) 23.5% cobaltand 0.25% nickel (calculated as metal).

Example 16 To 400 gms. of Example 15 alumina which had been heated for10 hours at 700 F. was added in 2 liters of water while stirring, 81gms. of cobaltous fluoride dihya pH of 3, giving a product (Sample 16-2)with 3.1%

iron and 11.3% nickel. Also, starting with 400 grams of the abovealumina and 2 liters of water and adding while stirring 167 gms. offerrous fluoride dihydrateat a pH of 3 and 162 gms. of cobaltousfluoride dihydrate gave a product (Sample 16-3) with 9.5% iron and 11.1%

cobalt.

Example 17 A series of catalysts were formed using the calcined aluminaof Example 15 by the following procedure: for each sample, 200 cc. ofthe alumina and 1 liter of water Were used as the starting materials.With the exception noted below, each sample was prepared by adjustingwith HF the pH of the water to 3, adding the specified amount of metalfluorides, stirring for 48 hours at room temperature, vacuum filtering,drying at 300 F. for about 6 hours, and then measuring the metalcontents. For Sample 17-1, 96 gms. of ferrous fluoride dihydrate and 48gms. of cobaltous fluoride dihydrate were added, the product analyzingas 17.5% iron and 9.1% cob-alt. For Sample 17-2, 167 gms. of ferrousfluoride dihydrate were added, the resulting product containing 19.3%Fe. For Sample 17-3, 84 gms. of ferrous fluoride dihydrate and 104 gms.of nickelous fluoride tetrahydrate were added, the product containing11.1% Ni and 8.06% Fe. For Sample 17-4, 30 gms. of ferrous fluoridedihydrate, 163 gms. of nickelous fluoride tetrahydrate, 7.1 gms. ofcupric fluoride dihydrate, 4.8 gms. of chromic fluoride tetrahydratewere added, the product showing 3.6% Fe, 16.3% Ni, 4.9% Co and 0.4% Cr.For Sample 17-5, 137 gms. of ferrous fluoride dihydrate and 43 gms. ofnickelous fluoride tetrahydrate were added, the product showing 4.6% Niand 14.8% Fe.

Example 18 A solution was made up with 10.58 gms. of antimonytrifluoride and 10 gms. of nickelous fluoride tetrahydrate by dissolvingfirst the nickelous fluoride and then the.

antimony trifluoride and the solution made up to 1 liter. Then 450 cc.of the above solution was used to contact 15 cc. of the samesilica-alumina as used in Example 1. After being mixed at regularintervals for 24 hours, the mixture was filtered and the catalyst driedfor 3 hours at 300 F. The resulting catalyst (18-1) contained 25.4 wt.percent antimony, 5.66 wt. percent nickel and 8.66 wt. percent fluorine.Also, 450 cc. of the antimony trifluoride-nickelous fluoride solutionwas contacted in the same manner as above with 15 cc. of the aluminaused in Example 5. After mixing at regular intervals for 24 hours andfiltering the catalyst was dried for 3 hours at 300 F. The resultingcatalyst product (18-2) contained 13.3- wt. percent antimony, 3.56 wt.percent nickel and 7.72 wt. percent fluorine In both the catalystproducts the nickel and antimony were highly dispersed on the supports.Nickel antimonide formed in such catalyst preparation gives a catalystparticularly on the acidic silica-alumina cracking support which can beused with:

out sulfiding for hydrocracking and light hydrocarbon conversions, thecatalyst having the hydrogenating component with a high melting point(1153 C. for nickel antimonide in the bulk). Other mixtures such asfluorides of nickel and arsenic can also be used to prepare catalystscontaining, for example, nickel arsenide and similar components can beformed with other metals such as cobalt.

Numerous other examples of catalysts preparation in accordance with thisinvention can be given by way of illustration. The aqueous metalfluorides mentioned here-,-

inabove can be used intreating alumina and/or magnesia- 12 2 containingsupports as described- There follows directions for making some of suchcatalysts Example 19 A calcined alumina 'inapowderedform is contactedwith a saturated solution of cupric fluoride until 20% Cu (calculated asmetal) becomes absorbed. .After drying the treated catalyst the copperis;converted substantially to the oxide, whereupon the catalyst issuitable for I use in oxidation-reduction reactions, such as forconversion of NO to N0 To illustrate that large amounts of metal: areadded in the metal fluoride treatmentof the .present invention,

the amount of metaladded .by one; metal fluoride treat--: ment inaccordance with the present invention was deter-- mined and comparedwith the amount of metal that would be deposited by evaporation of theWater from a :saturated metal fluoride solution just suificient involume to fill the pores of the alumina support treated.1 Theratio ofthe actual metal added to the catalyst supportto the.

amount of metal calculated from a pore volume of satu I rated solutionof the metal salt can be designated as the adsorption factor)? Withmetal salt :solutions of low concentration and large surface areaalumina-containing and having a pore volume of 0.89 cc./ gm. wasimmersed in 15 volumes of the metal salt solutions of the indicated saltcontents. and allowed to remain for 24 hours at room temperature. Afterdrying at 300 F. for 5 hoursthe treated alumina catalyst was analyzedfor metal content and in the cases'ofthe fluoride treated samples; alsofor fluorine content. The results are given in the following table:

TABLE I WtJPe'rcent On Treated Catalyst Metal Salt Concentration InTreating Solution (Moles/Liter) Adsorption Metal Salt Factor MetalFluoride H i i 2 core-romeo oo': menu Ni(NOz) For each test, one volume,of a .cal- I It will be noted that in all instances in Table I the.metal fluorideshave adsorption factors many times larger than thehighest of the other salts. Hence, the metal salts generally employed inpresent method have adsorp- .tion factors in the range of at least 15and preferably above 20.

The high surface area for addedmetal in the .metal. fiuoride-treatedalumina-containing .catalysts of the in'-' vention:can be illustratedbycomparing CO chemisorption values for added metal on an equal weightbasis when obtained ontthe catalyst support in the present metalfluoride treatment and other treatments such as by impregnationwithother salts such as the nitrates- The following Table II gives theCO chemisorption values fora series of catalysts of various metal.contents obtained by treating samples of silica alumina catalyst(containing 25% alumina and having a surface area of .500 and a pourvolume of 0.8 cc;/gm.) with NiF solutions andin another seriesimpregnating one or more times with nickel nitrate solutions.

It will be noted that the NiF treated catalysts have more than twice thesurface area per gram of nickel than the catalysts prepared byimpregnation with nickel nitrate. Further, the difference in surfaceareas are more pronounced at metal contents of about 3 to 10% by weightof nickel.

The catalyst of this invention is useful in a number of hydrocarbonconversion processes, but finds particular utility in operationsinvolving the conversion of hydrocarbon fractions to low boilingproducts at relatively low temperatures of about 400 to 700 F. In suchprocess the pressure ranges from 400 to 3000 p.s.i.g., and at least 150set. of hydrogen is introduced into the reactor for each barrel of feed.At preferred feed rates of 0.2 to 5 liquid hourly space velocity (LHSV),at least 20%, and generally 4070%, of the feed is converted to lowerboiling materials. In general, the feed material to be contacted with asulfided nickel fluoride on silica-alumina catalyst prepared by themethod of this invention can be any one of the conventional hydrocarbondistillate fractions boiling in the range of about 100 F. to 950 F., andhaving at total nitrogen content below about 100 p.p.m., usually below50 p.p.m., and preferably below p.p.m., which nitrogen content can beobtained by hydrofining or otherwise. Suitable feeds which can beemployed to provide such selected stock for treatment with the catalystof the present invention are those generally defined as fractionscontaining C O; and/or C hydrocarbons, light or heavy gasoline,naphthas, kerosene distillates, light or heavy gas oils, catalytic cycleoils, coker distillates and the like. These can be of straightrun originas obtained from petroleum, or they can be derived from variousprocessing operations, and in particular, from thermal or catalyticcracking stocks obtained from petroleum, gilsonite, shale, coal tar orother sources. The products of the hydrocarbon processes utilizing thecatalyst of the present invention will depend upon the aromatically orparaifinicity of the feed material and may comprise light branchedhydrocarbons such as isobutane and isopentane, high octane motorgasoline, a catalytic high octane reformer feed of high naphthenecontent, petrochemical intermediates such as xylenes, durene, etc., highquality diesel and jet fuels, low pour point fuels from high pour pointfuels'and the like.

The above process of hydrocracking hydrocarbon distillates and theimprovements obtained therein with the use of a catalyst prepared inaccordance with the present invention are described further and claimedin the application, Serial No. 220,086, filed August 28, 1962, under thetitle Hydrocarbon Conversion Process. Therein is disclosed that sulfidednickel fluoride silica-alumina hydrocracking catalysts prepared bytreating active silica-alumina cracking catalysts with aqueous nickelfluoride and subsequently sulfiding, are especially effective inconverting petroleum distillates and other hydrocarbon fractions tolower boiling products in a selective manner with a minimum loss to sidereactions. Moreover, these results are obtained with high per passconversions at relatively low temperatures. Furthermore, in spite oftheir high activity, these catalysts operate for long periods of timewithout fouling. Further, these catalysts, when properly prepared andused, retain their activity for a long time. The low fouling resultingfrom the use of the present fluoride-containing catalyst is surprisingsince fluoridecontaining catalysts heretofore proposed foul rapidly inlow temperature hydrocracking. Apparently, this unobv-ious effectresults from introducing the fluoride with the metal ion throughchemisorption of the metal fluoride on the activated silica-aluminasupport. In previous methods, the fluoride is introduced after the metalcomponent is deposited on the support, the fluoride usually being addedby treatment with aqueous hydrofluoric acid or anhydrous hydrogenfluoride or with decomposable fluoride compounds, the fluoride in thefinal catalyst composition being water soluble. By introducing thefluoride with the metal ion in the present method, the support is notattacked, and the surface area is even increased above that of thesupport.

The following examples illustrate further preparations in accordancewith the present invention, transformation of the added metal to sulfideform and use of the catalyst so prepared in hydrocarbon conversions.

Example 20 A sulfided nickel fluoride catalyst was prepared bycontacting 1 volume of powdered calcined (at 800 F.) silicaaluminacatalyst with 30 volumes of an aqueous saturated solution of nickelfluoride. After standing overnight the solution was decanted from thesolid catalyst and the solid filtered from the remaining solution. Thesolid was then dried atabout 300 F. for 3 hours. Analysis of thecatalyst showed 23% Ni and 9% F. Thereafter the catalyst was prereducedwith hydrogen at 900 F. for 3 hours.

Then the catalyst was placed in a reactor and hydrogen at ambienttemperature and pressure was passed through the reactor with thetemperature gradually being raised to 550 F. At this point the pressurewas raised to 1200 p.s.i.g. and the hydrogen stream admixed with normaldec-ane containing 2 vol. percent of dimethyl disulfide at 550 F.initially, with the proportion of hydrogen and dimethyl disulfide beingadjusted to give the equivalent of 0.6% of H 8 in the gas. With thestart of the sulfiding of the nickel the temperature quickly rose to 560F. and remained there for the remainder of the period of 4 /2 hoursduring which the n-decane contained dimethyl disulfide. The conditionsduring this period were as follows:

Average catalyst temperature F 560 Pressure p.s.i.g 1185 H feed (moleratio) 9.6 H rate (s.c.f./b.) 6,500 Space rate (LHSV) 8.0 Residence time(sec.) 14.7

Then, after passing hydrogen over the catalyst to sweep out excessdime-thyl disulfide, pure normal decane was passed over the sulfidednicked fluoride silica alumina catalyst. Within the first half hour thetemperature increased from 551 to 569 F., the other conditions for thereaction being as follows:

Pressure p.s.i.g 1185 H /feed (mole ratio) 9.2 H rate (s.c.f./b.) 6,300Space ra-te (LHSV) 8.0 Residence time (sec.) 15.3

During this perod the conversion was 91.3 Wt. percent to materialboiling below n-decane, of which material 93.6% boiled above propane and75.5% consisted of C to C isoparaflins.

The following examples illustrate that the metal fluoride treatedalumina-containing catalyst of the present invention have very lowfouling rates.

Example 21 this added to the hydrogen stream to give the equivalent of2% of H S in the gas. This sulfidirig treatment was continued untilthere was anamount, of sulfide equiv- I alent to 2.1 theories of H 8based on Ni S The catalyst was then employed in low temperaturehydrocrac'k- 7 ing of a hydrofined light cycle oil having the followinginspections:

Gravity, API 30 Aniline point, F. 93 Nitrogen (basic), ppm. 0.2Aromatics, vol. percent 48 Olefins, vol. percent 1 The reactionconditions were 6500 s.c.f. hydrogen per barrel of feed, 1200 p.s.i.g.total pressure, and a space velocity of 1.0 LHSV, with the temperaturebeing varied between 560 F. and 600 F. to give approximately 60%conversion of feed to product boiling below 400 F.

After 140 hours the temperature had been raised to about 590 F.Thereafter the run was continued an additional period (to a total of 322hours) within which the temperature for 60% conversion per pass variedbetween a 590 and 600 F., indicating very good resistance to foulmg. Theproduct during the latter period had a gravity of-about 46 API and ananiline point ranging from 108 114, which shows that very littlearomatic n'ngsaturatron occurred.

In a similar test with the same catalyst as above except that it wasprereduced at 900 F the run leveled out after 30 hours on stream atabout 550 F. and remained at such temperature until the run wasterminated at 70 hours.

No fouling of the catalyst was observed in this run. The

product had an aniline point of 117 F. and a gravity of about 46 API.

These runs illustrate that excellent conversions of hydrocarbon feed tohighly desirable products can be obtained with the present catalysts forvery long periods of time, from hundreds to thousands of hours. Incontrast, fluoride introduced into the catalyst separately from the.metal, as in prior methods, causes fouling of the nickel sulfidesilica-alumina catalyst when used in a hydrocrackmg process. Thus,fiuorided and sulfided nickel on silica-alumina catalysts prepared byimpregnating with nickel nitrate and treating with hydrogen fluoridegave much higher fouling rates. For example, such a catalyst prepared bynickel nitrate impregnation of silicaalumina beads to a 10.8% nickelcontent, treated with aqueous HF and then calcined at 800 F. beforesulfiding, gave a fouling rate of about 040 F./hr. (i.e., required suchtemperature increase to maintain conversions) when used with the feedand under the conditions set forth in Example 16 above. With a catalystprepared by impregnation of silica-aluminabeads with nickel nitrate to anickel content of about 25%, and then fluorided before sulfiding, thefouling rate was even higher.

The following example illustrates the improvement of the specialembodiment of removing the water-extractable fiuoride from the catalyst.

Example 22- A calcined silica-alumina catalyst in spray-dried,'pow-vdered form (containing 25% alumina and having a pore volume of 0.8cc./.gm.)- in an amout of 800 cc. was contasted with stirring for -78hours -withi6 liters of water' containing 623 gm. ofinickelous fluoride.The treated catalyst was filtered and then dried for 16 hours; at 300 FThe dried material was then pelleted into 8-14 mesh particles and heatedin air for 4 hours at 950 F. Then the particles were dividedinto threeparts andidentified.

as catalysts A, B and C.

Catalyst A was extracted with hot water in Soxhlet extractor for thirty:dumps. The extracted catalyst pellets were dr'iedand reducedin a flowingstream of hydrogen at 900 F. for .6 hours. The reduced catalystcontained 33.6% .Niand 5.7% F."

Catalyst B wasreduced inEa flowing-stream of hydrogen at 900 F. for 6'hours and then Soxhlet extracted for 30 dumps of ihot water. Thecatalysts then contained 30% Ni and 4.4%

Catalyst C: was reduced in a flowing stream of hydrogen at 900 F. for 6hours but was notextracted with water. This sample contained 32.7% Niand5.7% F.

All three catalysts were sulfided and subjectedto the activity test :asdescribed hereinabove, except :that the temperature of the test was. 570F. Also, the, aniline points of the products were measured.

The results of the =:above tests on the several catalysts were asfollows:.

Aniline Catalyst Activity Pt. of

. Index Product,

A (Water extracted after calcination) 32. 110 B (Water extracted afterreduction) 37. 7 126 C (No Water extraction) 23. 7 113 It will be notedthat the highest activity is obtained when the catalyst .prepared bynickel fluoride chemisorption is both calcined and .reduced before waterwashing,.

and hence, thismethod is preferred. 7

Also, catalystscan be preparedby the presentmethod for use in otherreactions as mentioned above and. illustrated in the following example:

Example :23

The catalyst preparedin-Example 6 hereinabove was placedin'areactor,which was pressured with p.s.i.g.

hydrogen sulfide and then up to 1000 p.s.i.g withhydrogen. The gaseswere recycled Iover the-catalyst for .4 hours at a rate of about, 3liters per hour, during which time the temperature wasv about 575 Afterthis sultiding step, the excess hydrogen sulfide was removed from thereactor.

through the reactor, as a feed, a middle cut of. a California crudeheavy gas oil having the following composition: 1

Then, hydrofining including nitrogen re-- moval was carried out withthis catalyst, by passing 117 After bringing the temperature upgradually to 800 F., the pressure was held at 1000 p.s.i.g. with a feedspace rate of 1.0 LHSV and a hydrogen flow rate of 4000 s.c.f./ barrelof feed. The product obtained had the following composition:

Average API gravity 27.2 Average mol. wt. 238 Aniline pt. 136 Basicnitrogen, p.p.m -6

As indicated above, the catalysts of the present invention have improvedactivity as compared to similar catalysts prepared by other procedures.The activities of catalysts for low temperature hydrocracking can betested by determining in the presence of'the catalyst the conversion ofa selected standard and readily obtainable hydrocarbon feed stock ofdefined physical and chemical characteristics, to products falling belowthe boiling point of said stock under defined operating conditions.

The feed stock employed is a catalytic cycle oil recovered as adistillate fraction from the effluent of a fluid type of catalyticcracking unit, the recovered fraction being one containing essentiallyequal proportions of aromatics and of parafiins plus naphthenes, andboiling over a range of from approximately 400 to 575 F., as determinedby ASTM D-l58, prior to any hydrofining treatment given the feed toreduce its basic nitrogen content to a level below 5 p.p.m., this beingthe maximum amount permitted in the test feed. The specific test feedemployed in obtaining the activity index values given herein wasobtained from a fluid catalytic cracking unit being charged with amixture of light and heavy gas oils cut from a Los Angeles Basin crude.This test stock was hydrofined by passing the same along with 3500s.c.f. hydrogen per barrel of feed through a hydrofining catalystcontaining cobalt oxide (2% cobalt) on a coprecipitatedmolybdena-alumina (9% molybdenum) support at a pressure of 800 p.s.i.g.,an LHSV of 1, and at a temperature between 700 F. and 750 F. Thishydrofining operation was accompanied by a hydrogen consumption of 300to 400 s.c.f. hydrogen per barrel of feed and resulted in a reduction ofthe basic nitrogen content in the liquid effluent to less than 5 p.p.m.The hydrofined test stock had the following inspections:

TABLE III INSPECTIONS OF TYPICAL HYDROFINED CYCLE OIL TEST SAMPLEGravity, API 30 Aniline point, F. 93 Nitrogen (basic), p.p.m. below 5Aromatics, vol. percent 48 Olefins, vol. percent 1 Paraffins plusnaphthenes vol. percent 51 ASTM distillation (D-15 8) Start 357 70 a-493 90 519 95 532 End point 570 Prior to hydrofining, the cycle oil hada gravity of 28 API, and ASTM D-158 start of about 400 F., and a basicnitrogen content of about 175 p.p.m. The reduction in ASTM start inhydrofining was due to a small amount of cracking.

The equipment employed in determining the activity index of the catalystis a conventional continuous feed pilot unit, operated once-through withhydrocarbon feed and hydrogen gas. It consists of a cylindrical reactionchamber operated down flow with a preheating section,

followed by a section containing the catalyst under test, and enclosedin a temperature controlled metal block to permit controlled temperatureoperation, together with the necessary appurtenances, such as feedburettes, feed pump, hydrogen supply, condenser, high pressure separatorprovided with means for sampling the gas and liquid phases, backpressure regulators, and thermocouples. For accuracy in hydrogen feed,hydrogen is compressed into a hydrogen accumulator or burette whence itis fed to the reactor by displacement with oil fed at constant rate froma reservoir by means of a pump.

In testing a catalyst to determine its activity index, the foregoinghydrofined cycle oil test stock, along with 8000 s.c.f. H per barrel offeed, is passed through a mass of catalyst (65 ml. were actuallyemployed) at a liquid hourly space velocity of 2 and at a furnacetemperature of 550 F., the actual feed rate employed being ml. per hour.The run is continued for 14 hours under these conditions, with samplesbeing collected at about twohour intervals. These samples are allowed toflash olf light hydrocarbons at ambient temperature and pressure,following which a determination is made of the API gravity of eachsample. The aniline point of the samples may also be determined when itis desired to obtain an indication of the relative tendency of theparticular catalyst to hydrogenate aromatics present in the feed. Theindividual API gravity values are then plotted and a smooth curve isdrawn from which an average value may be obtained. Samples collected atthe end of the eighth hour of operation are usually regarded asrepresentative of steady-state operating conditions and may be distilledto determine conversion to product boiling below the initial boilingpoint of the feed. This conversion under steady test conditions is atrue measure of the activity of the catalyst. However, the API gravityrise, that is, the API gravity of the product sample or samples minusthe API gravity of the feed, is a rapid and convenient method ofcharacterizing the catalyst which correlates smoothly with conversion.For convenience the foregoing API gravity rise is referred to as theactivity index of the catalyst.

While reference has been made above to the use of a particular catalyticcycle stock in connection with determining the activity index of thecatalyst, similar activity index values can be obtained with catalyticcycle stocks obtained from other than California crudes provided thesample employed as feed has substantially the same characteristics asthat of the feed described above. While the use of such other test feedsmay give slightly different absolute values than those described herein,such differences are without influence on conclusions reached relatingto catalyst activity inasmuch as the test stock is serving primarily asa relative standard by which to judge the conversion activity of thecatalyst.

The product aniline points determined by the method of the precedingparagraph, when compared with the aniline point of the feed, offer anindex to the capacity of the catalyst to produce a satisfactory balancebetween the simultaneous conversion reactions involvingdisproportionation-cracking, isomerization-cracking, and hydrogenation.

The low temperature hydrocracking catalyst prepared in accordance withExample 10 was pelleted with the aid of a small amount of hydrogenatedvegetable oil, oxidized with air at 950 F. for 4 hours to drive Off thevegetable oil, then reduced for 6 hours at 900 F., and thereafter placedin the reactor where it was sulfided in the manner described in Example15 above. The resulting catalyst was subjected to the above-describedactivity test and showed an activity index of 41.6. This illustratesthat the hydrocracking catalysts prepared by the present method givehigh conversions at relatively low temperatures. With such highactivities, the iso to normal ratio of the C to C paraffin fraction ofthe product is higher 19 for a given conversion than lower activitycatalysts prepared by other methods, since lower temperatures whichfavor such ratios can be used here. The above examples'are illustrativeof the improved method of obtaining metals, and compounds thereof, in

a state of high surface area on supports containing activated alumina ormagnesia. The examples also indicate that the catalysts produced by thisinvention are used advantageously on reactions which are. accelerated bythe surface of a metal or metal compound on a support. In

addition to the particular utility of sulfided nickel fluo-- rideon'alumina-silica' supports for low temperature hydrocracking, thecatalysts prepared in accordance with the method of the presentinvention are variously useful in other hydrocarbon conversions such'ascracking, hydrofining, dehydrogenation, oxidation, isomerization,reforming and the like. For instance, a dehydrocyclization catalyst maybe prepared by first soaking powdered cal-3 without departing from thespirit or scope of the disclo-' sure or scope of the appended claims.

We claim:

1. The method of preparing improved catalysts having catalyticallyactive metals in a highly dispersed state on a support containing atleast one metal oxide selected from the class consisting of alumina andmagnesia, said catalytically active metals havinghydrogenation-.dehydro-r genation activity, which method comprisescontacting said metal oxide support in a substantially dehydrated stateand having a relatively high surface area for at least three hours withan aqueous solution of a fluoride of at least one of said metals for asufiicient time and with sufiicient metal fluoride present tochemisorbat:least one weight percent of metal fluoride, calculated as metal, on 1said support and washing the catalyst with wat er to .re-' movesubstantially all the water-soluble fluorides remaining on-the supportand leaving the chemisorliedmetal fluorides on the support.

2., The method of, claim 1 wherein the catalyst is subjected to areducing atmosphere beforethe washing step and the washedic'atalyst isdried and then sulfided with a gaseous sulfiding agent. i I I 3. Themethod of claim ,1 wherein said aqueous solution contains a plurality ofmetal fluorides. i

4. A catalyticprocess for selectively converting during a single contactwith catalyst, at' least 20% 'of hydrocarbon feed of low nitrogencontent'to products boiling below the initial boiling point'of saidfeed'with a minimum loss of feed to undesirable side reactions; whichcomprises passing said feed, alongwith at least;1500=s.c.f. of hydrogenper barrelv of said feed andwith the-consumption of t,

at least 500 s.c.f. of hydrogen per barrel of. said feed converted tolower boiling products, at more than 350 p.s.i.g.

hydrogen partialpressure and below-750'F.' at more than 0.2 v./v./hourliquid hourly space velocity, over a sulfided nickel fluoride:silicaealurnina :catalystpreparedby chemisorbing 5 to 40%, on a dryweight basis, of nickel i fluoride on an active alumina-containingcracking support,removing residual:water-extractable fluoride, and.leaving chemisorbed metal fluoride on said support and sulfiding the;resulting driedfluoride-containing catalyst.

References, Cited by the Examiner UNITED? STATES PATENTS 2,914,46111/1959 Ciapetta 208-111 2,944,005 7/1960 Scott 205l09 3,117,076 1/1964Brenneretal. 208139 PAUL M. COUGHLAN, Primary Examiner.

ALPHONSO D. SULLIVAN, Examiner.

4. A CATALYTIC PROCESS FOR SELECTIVELY CONVERTING DURING A SINGLECONTACT WITH CATALYST, AT LEAST 20% OF HYDROCARBON FEED OF LOW NITROGENCONTENT TO PRODUCTS BOILING BELOW THE INITIAL BOILING POINT OF SAID FEEDWITH A MINIMUM LOSS OF FEED TO UNDERSIRABLE SIDE REACTIONS, WHICHCOMPRISES PASSING SAID FEED, ALONG WITH AT LEAST 1500 S.C.F. OF HYDROGENPER BARREL OF SAID FEED AND WITH THE COMSUMPTION OF AT LEAST 500 S.C.F.OF HYDROGEN PER BARREL OF SAID FEED CONVERTED TO LOWER BOILING PRODUCTS,AT MORE THAN 350 P.S.I.G. HYDROGEN PARTIAL PRESSURE AND BELOW 750*F. ATMORE THAN 0.2 V./V./HOUR LIQUID HOURLY SPACE VELOCITY, OVER A SULFIDEDNICKEL FLUORIDE SILICA-ALUMINA CATALYST PREPARED BY CHEMISORBING 5 TO40%, ON A DRY WEIGHT BASIS, OF NICKEL FLUORIDE ON AN ACITVEALUMINA-CONTAINING CRACKING SUPPORT, REMOVING RESIDUAL WATER-EXTRACTABLEFLUORIDE, AND LEAVING CHEMISORBED METAL FLUORIDE ON SAID SUPPORT ANDSULFIDING THE RESULTING DRIED FLUORIDE-CONTAINING CATALYST.